Abstract: Various embodiments of the disclosure provide a device performing communication and a method for operating the same. According to an embodiment, an operation method comprise receiving, by the AMF, a registration request message from a user equipment (UE) through a base station, the registration request message including network slice selection assistance information (NSSAI) requested from the UE, identifying, by the AMF, whether the requested NSSAI can be serviced, transmitting, by the AMF, a message for requesting a target AMF capable of servicing the requested NSSAI to a network slice manager (NSM) through a network slicing selection function (NSSF) when the requested NSSAI cannot be serviced, and receiving, by the AMF, information regarding the target AMF from the NSM through the NSSF and transmitting the information regarding the target AMF and NSSAI allowed by the target AMF to the base station.